Wagyu translates to "Japanese Cow." Most Wagyu we consume is from the Japanese Black (Kuroge Washu) breed. By law, wagyu in Japan are Fullblood (100% wagyu genetics) with no cross-breeding.
Fullblood Wagyu are genetically unique to have the highest intramuscular fat (marbling) and have a low melting point of ~ 78°F, resulting in the famous melt-in-your-mouth experience.
Japan used to export live Fullblood Wagyu to the world. In 1997, though, Japan declared the Wagyu breed a living national treasure and banned exports. Today, there is a small amount of Fullblood Wagyu outside of Japan.
WHAT DO THE F NUMBERS MEAN?
• higher F numbers = more wagyu DNA
• most are F1 and F4 are the rarest
Farmers achieve genetic variations by crossing Wagyu with Angus. Higher percentages of Wagyu genetics lead to higher F numbers and more Wagyu characteristics in the beef. Most Wagyu in the U.S. & Australia are F1 Crosses (50% wagyu).